Compounds having peroxy and aliphatic azo groups and methods using these as initiators

ABSTRACT

I. Compounds having independent peroxidic (X) and aliphatic azo groups of the formula

United States Patent [191 Sheppard et al.

1 1 Jan. 14, 1975 COMPOUNDS HAVING PEROXY AND ALIPHATIC AZO GROUPS ANDMETHODS USING THESE AS INITIATORS [75] Inventors: Chester StephenSheppard,

Tonawanda; Ronald Edward MacLeay, Williamsville, both of N.Y.; RichardAnthony Bafford,

[21] Appl. No.: 409,107

Related US. Application Data [60] Division of Ser. No. 37,310, May 14,1970, Pat. No. 3,812,095, which is a continuation-in-part of Ser. No.703,241, Feb. 6, 1968, abandoned.

[52] US. Cl. 260/886, 260/875, 260/876 B, 260/885, 260/901 [51] Int. Cl.C081 19/10 [58] Field of Search 260/885, 882,901, 875, 260/886 [56]References Cited UNITED STATES PATENTS 3,644,584 2/1972 Fryd 260/8753,649,614 3/1972 Sheppard et al U 261N885 3,652,724 3/l972 Shimomura etal 260/877 3,706,818 12/1972 Mageli et al 260/885 FOREIGN PATENTS ORAPPLlCATlONS 856,581 12/1960 Great Britain 260/875 857,145 12/1960 GreatBritain 260/885 Primary Examiner-Murray Tillman AssistantExaminer-Thurman Kennis Page Attorney, Agent, or FirmPlumley & Tyner[57] ABSTRACT 1. Compounds having independent pcroxidie (X) andaliphatic azo groups of the formula l( m .ln Example: di-t-butylperoxyester of cis4,4'-azobis-(4- cyanovaleric acid). II. A method of making ablock polymer where vinyl monomer is initiated sequentially to producein one instance: a polymer having azo-carbon linkages present, which isthen reacted with vinyl monomer under conditions to rupture theazo-carbon linkages, and in another instance: a polymer havingperoxy-carbon linkages present, which is then reacted with vinyl monomerunder conditions to rupture the peroxy carbon linkages.

4 Claims, No Drawings COMPOUNDS HAVING PEROXY AND ALIPHATIC AZO GROUPSAND METHODS USING THESE AS INITIATORS This is a division of applicationSer. No. 37,310, filed 05-14-1970, and now US. Pat. No. 3,812,095, whichin turn is continuation-in-part of application Ser. No. 703,241, filed02-06-1968 and now abandoned.

BACKGROUND OF THE INVENTION l (mgyooc-n-ulowg thermalpolymerizationinitiators i.e. they will generate free radicals either by irradiationor by heating, which is typical for conventional azo and peroxideinitiators. In each of these compounds (I), (3), (4) and (5), the peroxyand azo groups are attached to the same carbon atom. Thus, thesecompounds undergo simultaneous azo and peroxide decomposition andconsequently cannot be used as sequential free radical generators in themanner that the novel compounds of the present invention can be used.The compounds of this invention contain azo and peroxide groups whichare not linked to the same carbon atom and therefore sequentialdecomposition can and does occur, as illustrated in the Examples.

In compound (2), the azo portion of the molecule is not a free radicalgenerator, at least in the broad temperature range where vinylpolymerizations are conventionally carried out. The peroxide portion isa free radical generator useful for vinyl polymerizations. The

O l Cas 'Q 3 s 3): 1.. 2 5: 8. a

CH -C-N-N-C-CH3 3 I 1 O O O O (CH C c(cn n' -c-N-N-R' o O K azo portionin this structure is attached to two phenyl or substituted phenylradicals and structures of this type are typical azo dyes. Thesestructures are known to be stable and absorb certain wavelengths ofvisible light. Thus, the azo portion of compound (2) can be used toactivate the peroxide portion by visible light and it can also be usedas a dye to impart color, but it does not decompose to give freeradicals under conventional vinyl polymerization conditions. Compoundsof -c1, Br, -ocn, OCR7, -SCR7,

structure (2) cannot be used as sequential free radical generators inthe manner. that the novel compounds of SUMMARY OF THE INVENTION 1.Compounds The compounds of the invention include independent peroxidicand aliphatic azo groups and have the formula:

where l. m is an integer equal to l-2;

2. n is a number equal to l-lO; 3. R is 4. X is a peroxy containingradical selected from 5. R and R may be the same or different and arealkyl or cycloalkyl radicals having l-l carbon atoms;

6. R is selected from -CN,

0 Q a H -CNH2, COR6, CNHZ, CR6,

O 9 R9 C C R7, N R8, N I

O n NO2, -No -05 CR or -0COR7 7. R is a tertiary aliphatic radicalhaving 4l() carbon atoms;

8. R and R' may be the same or different and are aliphatic diradicalshaving 12() carbons which diradicals optionally contain in the backbonestructure one or more non-adjacent oxygen, sulfur or nitrogen atoms;aromatic diradicals having 6-12 carbons; or aromaticaliphatic diradicalshaving 7-2O carbons optionally containing in the backbone structure oneor more non-adjacent oxygen, sulfur or nitrogen atoms;

9. R is a lower alkyl radical (normally containing 1-6 carbon atoms);

10 R is an alkyl or cycloalkyl radical of ll 0 carbons or an aromaticradical of 6-12 carbons;

11. R is a lower alkylene diradical (usually having 1-8 carbons);

12 R is hydrogen, an alkyl or cycloalkyl radical of l-10 carbons, or anaromatic radical of 6-12 carbons;

13. R and R together with the tertiary carbon atom in R can form acycloalkyl triradical of 3-10 carbons; and

14. R is (a) a tertiary aliphatic radical of 4-10 earbons, (b) R'-X or(c) R when m is l and X is a diradical.

SUMMARY OF THE INVENTION 11. Methods of Polymerization A. One method ofthe invention prepares a block polymer by:

1. forming a polymer having azo groups present by reacting vinyl-typemonomer and an azo-peroxy compound as above under vinyl polymerizationconditions, controlling conditions in order to cause the peroxy-oxygenlinkages to rupture prior to rupture of the azo-carbon linkages, saidrupture of the peroxy-oxygen linkages having the effect of initiatingsaid polymerization; and l 2. reacting vinyl-type monomer with thepolymer of step (1) under conditions to rupture the azocarbon linkagesof said step l) polymer to produce a block polymer product.

B. Another method of the invention prepares a block polymer by:

1. forming a polymer having peroxy groups present by reacting vinyl-typemonomer and an azo-pcroxy compound as above under vinyl polymerizationconditions, controlling the conditions in order to cause the azo-carbonlinkages to rupture prior to SCOR -SCOR OR -N -SCN, -NCS, OCN, OOR OOCR-OOH, -OH,

rupture of the peroxy-oxygen linkages, said rupture of the azo-carbonlinkages having the effect of initiating said polymerization; and

2. reacting vinyl-type monomer with the polymer of step (1) underconditions to rupture the peroxyoxygen linkages of said step (1) polymerto produce a block polymer product.

DETAILED DESCRIPTION OF THE INVENTION 1. Compounds The compounds of theinvention have the general formula and may be simple compounds, when nis 1 and m is l or 2, or polymeric" compounds when n is 2-10.

In the definition of R as the diradical 31 (=N) -'c R5 (X).

the azo nitrogen (=N) and peroxy radical (X) are shown in order to setout the relation of the groups to the R group.

R and R can be any aliphatic or cycloaliphatic radical having up tocarbon atoms or more. Commonly they are alkyl radicals.

X and R are as defined in the aforesaid Summary of the Invention (I.Compounds).

R can be any aliphatic, cycloaliphatic, or aromatic radical,particularly an alkyl, phenyl, or cyano radical, and also an alkoxy,aryloxy, acyloxy, alkoxycarbonyl,

alkoxycarbonyloxy, aroyloxy, carbamoyl, azido, chloro, bromo,thiocyanato, isothiocyanato, thioacyloxy, dithioacyloxy, alkoxyimidoyl,amidoyl,

alkoxythiocarbonyloxy, alkoxydithiocarbonyloxy, alkylthiol, arylthiol,cyanato, tertiary alkylperoxy, acylperoxy, hydroperoxy, hydroxyl, nitro,nitrato, diacylimido, Z-substituted-l,3,4-oxadiazol-4-yl, and alkyl orarylacetylino radical.

R and R' can be any aliphatic or aromatic-aliphatic diradical having upto carbons and optionally containing one or more non-adjacent oxygen,sulfur, or nitrogen atoms in the backbone structure, or an aromaticdiradical having 6 to 12 carbons.

R is an alkyl radical normally containing 1 to 6 carbons.

R can be any aliphatic, cycloaliphatic, or aromatic radical,particularly a lower alkyl of 1 to 6 carbons and a phenyl or a loweralkyl and a chlorine substituted phenyl radical.

R can be any aliphatic diradical, particularly a lower alkylenediradical containing up to 8 carbons.

R can be hydrogen or any aliphatic, cycloaliphatic or aromatic radical,particularly a lower alkyl radical of 1 to 6 carbons and a phenyl orsubstituted phenyl radical.

In the diradical I t r r -c-oo-c -c-ooA- R',,, one tertiary carbon andone R together can form a 5 cycloaliphatic diradical.

R can be (a) a tertiary aliphatic radical haying 4-10 carbon atoms,particularly a talkyl radical, or (b) the combination radical R-X or (c)when m is l and X is a diradical included in the above definition, R canbe R.

The compound may be open-ended or may be closed, i.e., cyclic. Example 1shows a cyclic compound where R=R=-(CN )C(CH )CH CH m=n=l; and X is-(O)-COO-C(O).

Several illustrative compounds of the invention are prepared in theworking examples set forth herein.

Utility The compounds of the invention may be used in any operation orreaction where a corresponding azo compound, in the absence of theperoxy group, or a corre sponding peroxy compound, in the absence of theazo group, could be used taking into account the effect of the azo groupwhich is present. Thus these compounds can be used as cure initiatorsfor mixtures of vinyl monomers and unsaturated polyester resins. lm-

' portantly, they are initiators for polymerization reactions,especially polymerization of vinyl-type monomers. The initiator may beselected to give simulta neous, or essentially so, rupture of both theazo and peroxy groups or give sequential rupture. The use of compoundshaving different rates of rupture at a given condition permits theformation of polymers having either azo groups or peroxy groups as apart of the polymer. These polymers are ideal for the preparation ofblock or graft polymers and this is a preferred use of the compounds ofthe invention. Examples 6, 7 and 20 illustrate this preferred aspect ofthe invention.

Methods of Preparation The compounds of this invention can be preparedby one or more of the following general techniques: (A) The peroxidationof suitably substituted aliphatic azo compounds (an especially suitableclass of such azo compounds are those that contain acylatingfunctionalities e.g. acid chloride, chloroformate, and anhydridegroups); of acid chlorides or anhydrides to diacyl peroxides or toperoxyesters; of chloroformates to peroxydicarbonates or tomonoperoxycarbonates; of ketones to diperoxyketals; and of tertiaryalcohols to dialkyl peroxides or hydroperoxides (Examples 1-5, 9, 11,13-16, 28 and 3645). (B) The coupling of a peroxide and an aliphatic azocompound each containing a functional group that will interact to linkthe azo to the peroxide. Coupling reactions are well known to the artand involve well known organic reactions such as esterification,amidation, etherification, carbonate formation and many others.Especially suitable compounds for these coupling reactions are azocompounds containing acylating functions; peroxides containing acylatingfunctions; hydroxy containing diperoxyketals; and other various knownperoxides and azo compounds containing functionalities such as carboxyand hydroxy groups (Examples 10, 12, and 1820)..(C) The conversion ofthe ketone group in peroxides containing a kctone functional group to analiphatic azo compound. (Examples 21-27 and 29-35).

Description ll. Methods of Polymerization The method inventions aredirected to the use of compounds of the invention to prepare blockpolymers by a sequential procedure wherein a compound I is used toinitiate vinyl polymerization to prepare a polymer including either azoor peroxy groups as a part of the polymer as determined by the conditionunder which the polymerization is carried out. The azo or peroxy groupcontaining polymer is then further polymerized with vinyl monomer underconditions to rupture the azo or peroxy group whereby the block polymeris formed.

These sequential and/or preferential decompositions of the azo andperoxide portions of the molecule can be accomplished by a variety oftechniques. One method is to use two different temperatures, takingadvantage of the difference in the thermal rates of decomposition of theazo and peroxide portions of the molecule. Another method, also based onthe different thermal rates of decomposition, is to use the sametemperature but different reaction times. For example, the peroxideportion of the azo-peroxide of Example 3 would be 50 percent decomposedafter 13 minutes at 70C while the azo portion would be less than 4percent decomposed in this time, but the latter would be 50 percentdecomposed after 179 minutes at this same temperature.

Still another method is to use an activator for the peroxide portion,e.g., amines, transition metal salts, etc., which will keep the azoportion intact since the azo structures in Compound I are insensitive tosuch activators. The azo portion can then be subsequently decomposedeither thermally or by irradiation (e.g., ultraviolet). Still anothertechnique is to decompose one portion (either azo or peroxide) thermallyand subsequently decompose the other portion by irradiation orvice-versa. Another method is to use two different irradiation sourcesin sequence where one source preferentially attacks one portion and thesecond radiation source preferentially attacks the other portion of theazo-peroxide molecule.

Thus, by taking advantage of the difference in the physical and chemicalproperties of the novel azoperoxides of Compound I, a variety oftechniques can be used for sequential free radical generation.Sequential free radical generation is very useful in the vinylpolymerization field. Block copolymers can be made from any combinationof polymerizable vinyl monomers.

Sequential free radical generation is also employed in the conventionalpolymerization of ethylene and styrene. The present art accomplishesthis by using two or more polymerization initiators of different thermalstability.

Any vinyl-type monomer that can be polymerized by free-radicals can beused to prepare the azoor peroxide-containing polymers and anycombination of different vinyl monomers can be used to make the blockpolymers. Typical vinyl monomers include: styrene, vinyl chloride, vinylacetate, ethyl acrylate, methyl methacrylate, butadiene acrylonitrile,acrylamidc, acrylic acid, methacrylic acid, vinyl carbazole,vinyltoluene, vinylpyridine, vinylidene chloride and the like.

Conventional polymerization techniques, i.e. bulk, solution, suspensionor emulsion polymerizations, can be used. The choice will depend uponthe normal reasons for choosing one technique over another c.g. waterand oil solubility of the monomer and/or initiator; desired molecularweight range of the polymer; temperature (or exotherm) control; etc.

The temperatures at which the polymerizations are carried out willdepend upon the polymerization technique; the monomer, solvent orsuspending medium; and the physical properties desired in the polymer;but most of all upon the azo-peroxide initiator and the method chosen todecompose the azo or peroxide portion of the initiator. Activation ofthe peroxide portion by amines, reducing agents, transition metalcarboxylates, etc., can be carried out from below -20C up to its normaldecomposition temperature. The same is true for activation of theperoxide or azo portions by irradiation Irradiation sources can beultra-violet radiation, and in the presence of photosensitizers (eg,certain azo dyes) visible light can also be used. The temperatures usedfor the thermal decompositions of the azo or peroxide portions willdepend upon the thermal stability (half-life) of the azo or peroxidegrouping in the molecule. These halflives can be determinedquantitatively for each azo-peroxide compound by conventional methodsi.e., gas evolution, and iodometric, ultra-violet, or gaschromatographic analytical techniques to determine the rate ofdisappearance of each portion (azo or peroxide) at any giventemperature. (Such half-life data were determined for the compounds madein Examples 1 to 5).

However, it is not necessary to accurately determine the half-life ofeach portion since most halflives can be predicted, within a fewdegrees, from the closest analogous monomeric azo or peroxide structure,many of which are well known. Such 10 hour half-life temperature rangesof some typical peroxide and azo structures are given in Tables I andII. (More accurate data is available on the individual compounds whereR,R',R" and R' are known and such data was used to estimate thehalf-life ranges on the compounds prepared in Examples 8 to 19.)

There are many literature references to fill in the conditions forcarrying out the methods as a matter of ordinary skill i.e. all thevinyl monomers can be polymerized by a peroxide or azo initiator; azoand peroxide initiators are commonly used in all four freeradicalpolymerization techniques; and it is old in the art to activateperoxides with amines, transition metal salts, reducing agents and toactivate both azo and peroxide initiators with ultra-violet radiation orvisible light in the presence of photosensitizers.

TABLE I Ten-Hour Half-Life Temperature Ranges of Various Peroxideat-Allqrl Peroxyeatera 10 Hour Half- TABLE I (Cnnt'd) 10 Hour Half-LitePeroxide Class General Structures Ragga C II R"CHOOOR 66.79

xi iil R"-C-CO0R 51.55

3. c-L-coo 5- a Diaoyl Percmidea (n'cu co-) 61-69 (R"-(|IH-CO-)2 RIQ-l-o- 5 -75 n RI I l RI I i J 1 Diallwl Peroxide: R" I-O--0-Y--R"117-128 I RI R" R Diperoxyketala c 0 O-AIJQ'J. 0,0-t-A11qrl \l 99Monoperozqrcarbonates R OCOOR Peroaqrdicarbonates R OCOOCORHydroperoxidea ROOH 155-172 c.

where: R t-alxqrl radical R, R", R'" aliphatic or aromatic radicals;

*Allqrland arallql hydroperoxides are more generally used at lowtemperatures in combination with redox catalysts in emulsion vinylmonomer polymerizations.

TABLE II Ten-Hour Half-Life Temperatures of Various Azo CompoundsGeneral Structure 10 Hour t /2 range, C

3 3 CH -CI N-N-(II-CH ON CN B l t-CnH -N'N-(f-R' when:

R =R'==CH 79 Ii -33; R'-(CH CHCH 7?;8

R-CH i R'-ROCCH CH2 76-79 i R-CH 'm-ncocn 77-80 R R --(CH 55 *3 F3 Gl'l3(l3N-N-(l!-CH 162 CH CH2 0 2 0 01-1 6 0 O CCH EXAMPLES Compound I whereR=R Illustrative embodiments of compounds of the invention and uses ofsome of these in methods of the inven- CH tion are set forth in thefollowing examples, which are 3 not to be considered as limiting thescope of the inven- -C'-c1-I Cfl tion.

EXAMPLE 1 Preparation of 6,9-Dimethyl-6,9-dicyano-A 1,2diom l; n l; andxa-7,8-diazacyclododecan-3,12-dione.

e e it I 2 2 To a solution containing 2.0g (0.028 mole) of 50 perl centhydrogen peroxide and 4.8 g. (0.0616 mole) of 50 Q percent sodiumhydroxide in ml. of water was o added 30 ml. of methylene chloride. Theresulting mix- I ture was cooled to 10C and stirred while a solution 0 0containing 8.4g. (0.0264 mole) of the diacid chloride ofcis-4,4'-azobis-(4-cyanovaleric acid) in 50 m1. of methylene chloridewas added during a 40 minute period, keeping the reaction temperature at8 to 10C throughout the addition. The reaction mixture was stirred foran additional 3 hours at C to C. Then, 30 m1. of a saturated solution ofsodium bicarbonate was added, and the reaction mixture stirred forminutes at 10C. The methylene chloride layer was separated, cooled to 0to 3C, and washed twice with 40 ml. solutions of 5 percent sodiumbicarbonate, then three times with ml. solutions of 3 percent potassiumhydroxide, then twice with water, dried over anhydrous sodium sulfateand filtered. The resulting methylene chloride solution was concentratedto about 40 ml. and allowed to stand at 20C to crystallize for severaldays. The methylene chloride solution was decanted and the white solidremaining was dried under vacuum at 0C. The methylene chloride solutionwas concentrated further and again stored at 20C to obtain a second cropof crystallized product. The combined products weighed 2.6 grams (35.4percent yield) and additional product was still present in the methylenechloride mother liquors.

The product did not melt upon heating to 103C at which point it explodedwith a loud pop. Its infrared spectrum was in agreement with thestructure of 6,9-dimethyl-6,9-dicyano-Al,2-dioxa-7,8-diazacycloododecan-3,1 2-dione, showing absorption bandsfor the cyano and diacyl peroxide groups. The product is sensitive toshock and decomposition rate studies indicated that the diacyl peroxideportion decomposed at a significantly faster rate (1/2 99 minutes at70C) than the azo portion of the molecule (l/2 236 minutes at 70C) ino-dichlorobenzene. The product can be stored at -20C for more than 1month.

EXAMPLE 2 Preparation of the Polymeric Peroxide of trans-4,4-Azobis(4-cyanovaleric acid) Terminated with Carboxylic Acid Groups.

0 CH 0 H 2)2 l H H )2c-0 H CH CN Compound I where R=R'= m= 1,n=4.3, andX= O O I l l To a stirred solution containing 2.29g. (0.057 mole) ofsodium hydroxide and 0.965g. (0.028 mole) of hydrogen peroxide in 30 ml.of water was added a mixture containing 3.0 g. of sodium dihydrogenphosphate, 3.0g. of disodium hydrogen phosphate and 60 ml of water at 0to 5C. To this stirred solution was added, dropwise, over minutes, asolution of 8.5 g. (0.027 mole) of the diacid chloride oftrans-4,4'-azobis(4- cyanovaleric acid) in 60 ml. of methylene chloridekeeping the temperature below 3C throughout the addition. The reactionwas stirred cold for an additional 1 /2 hours and then filtered. Thesolid product was washed with methylene chloride and water and thendried. lt weighed 4.9g. (66.2 percent yield) and had an active oxygencontent (determined by iodometric titration) of 4.4 percent whichcorresponds to an average n value in the above structure of 4.3. Theproduct was sensitive to shock and decomposed at 106C with a loud pop.

An additional 1.8g. (24.3 percent yield) of lower molecular weightproduct (average n =1 .585) with an active oxygen contect of 1.68percent was obtained from the aqueous-methylene chloride filtrate byevaporating off the methylene chloride with a stream of nitrogen gas.This product was less shock sensitive than the first isolated productabove.

The infrared spectra of both products were in accord with the abovestructure. Decomposition rate studies on the first product indicatedthat the peroxide linkages decomposed significantly faster (t r 369minutes at 60C and 102 minutes at C) in water than the azo linkages (t 7860 minutes at 60C and 231 minutes at 70C).

This product cured an unsaturated polyester resinstyrene material at Cto a hard thermoset.

EXAMPLE 3 Preparation of the Polymeric Peroxide of trans-4,4-Azobis(4-cyanovaleric acid) Terminated with Sodium Carboxylate Groups.

To a stirred solution containing 0.72g. (0.018 mole) of sodium hydroxideand 0.225g. (0.0066 mole) of hydrogen peroxide in 13 ml. of water wasadded, dropwise, a solution containing 1.9g. (0.006 mole) of the diacidchloride of trans-4,4'-azobis(4-cyanovaleric acid) in 12 ml. ofmethylene chloride at 0 to 5C. A white precipitate formed. The reactionmixture was stirred for two hours and then filtered. The solid productwas washed with water and methylene chloride and then dried undervacuum. lt weighed 0.8g. (41.2 percent yield) and decomposed at 97C witha loud pop.

The product was sensitive to shock and its infrared spectrum was inagreement with the above structure. The active oxygen content,determined by iodometric titration, was found to be 3.27 percent, whichcorresponds to an average n value in the above structure of 2.62.

The product is partially soluble in water and decomposition rate studiesin water indicated that the peroxide linkages decomposed significantlyfaster (t =13 minutes at 70C) than the azo linkages (t =17) minutes at70C).

EXAMPLE 4 Preparation of the Di-t-butylperoxy Ester of cis-4,4'-Azobis(4-cyanovaleric acid).

Compound I where R=RX and R m l, and n 1.

To a solution containing 3.8g. (0.012 mole) of the diacid chloride ofcis-4,4'-azobis(4-cyanovaleric acid) in 40 ml. of methylene chloride wasadded 2.18g. (0.024 mole) of 99.3 percent pure t-butyl hydroperoxide at05C. The resultant solution was stirred at 5C while 1.9g. (0.024 mole)of pyridine in an equal volume of methylene chloride was added. Thereaction mixture was stirred at 0-3C for 4 hours and then allowed towarm to 21C at which point it was cooled to below C and washed with ml.water. The cold methylene chloride reaction solution was then given thefollowing washings: 1) once with 20 ml. of dilute hydrochloric acid; 2)once again with 20 ml. of water; 3) once with 20 ml. of 5 percent sodiumsulfite and 5 percent sodium acetate solution; 4) twice with 20 ml. of a5 percent sodium bicarbonate solution; and 5) twice with 20 ml. ofwater. The resultant methylene chloride solution was dried overmagnesium sulfate, filtered, and the methylene chloride evaporated toobtain 4.0g. (78.6 percent yield) of the di-t-butylperoxy ester ofcis-4,4-azobis(4-cyanovaleric acid) m.p. 104-l 06C with decomposition.

The product had an active oxygen content (found by iodometric titration)of 7.37 percent indicating a purity of 97.7 percent. The infraredspectrum of the product was in agreement with the above structureshowing perester carbonyl and t-butylperoxy absorption bands and nocarboxylic acid, acid chloride or hydroxyl absorption bands.

The product's infrared spectrum was not changed after standing for twodays at 21C indicating room temperature stability. It was onlymoderately sensitive to shock. Decomposition rate studies intrichlorobenzene indicated that the azo portion decomposed at asignificantly faster rate (t '-92 minutes at 80C) than the peresterportion of the molecule (t 319 minutes at 80C).

EXAMPLE 5 Preparation of the mono-t-Butylperoxy Ester of the DiacidChloride of trans-4,4'-AZobis(4-cyanovaleric acid).

Compound I where m =1. n l, and R a a GIG-(GE hf- CH 0 and X JSOOCgH-fi,

To a stirred cold (0-2C) solution containing 2.l8g. (0.024 mole) of 99.3percent pure t-butyl hydroperoxide and 1.35g. (0.024 mole) of potassiumhydroxide in 41.5 ml. of water was added, over a ten minute period, asolution containing 3.8g. (0.012 mole) of the diacid chloride oftrans-4,4'-azobis(4-cyanova|eric acid) in 30 ml. of methylene chloride,keeping the reaction temperature at 02C throughout the addition. Thereaction mixture was stirred cold for an additional 18 minutes and thelayers were then separated. The methylene chloride layer was washedtwice with 10 ml. portions of a 5 percent sodium bicarbonate solution,once with water, dried over magnesium sulfate, and filtered. Themethylene chloride solvent was evaporated to obtain 4.6g. (theory 4.5g.)of a low melting product.

Recrystallization from benzene-pentane at -7C gave 2.55g. of productthat had an active oxygen content of 4.30 percent (theory 4.32 percent).Its infrared spectrum was in agreement with the above structure showingboth peresters and acid chloride carbonyl absorption bands.Decomposition studies in dioctyl phthalate at C indicate that both theazo and perester linkages decompose simultaneously at this temperature,the product having a half-life of about 28 to 32 minutes. Apparently,the perester undergoes induced decomposition at this relatively hightemperature.

EXAMPLE 6 A. Preparation of an Azo Containing Polystyrene Using theAzo-Peroxide Initiator of Example 1.

To 20g. of styrene was added 0.7285g. of 6,9-dimethyl-6,9-dicyano-Al,2-dioxa-7,8-diazacyclododecan- 3,12-dione (from Example 1) dissolvedin 3g. of methylene chloride. The reaction mixture was kept undernitrogen in a sealed tube at 50C for 24 hours and then dissolved inbenzene. The polystyrene was obtained by precipitation from the benzenesolution by adding methanol. It was again taken up in benzene andreprecipitated with methanol. After still another reprecipitation,5.245g. of azo containing polystyrene was obtained.

A blank, run under the same conditions but without an initiator, gaveonly a 0.5 percent conversion of styrene to polystyrene by thermalpolymerization.

B. Preparation of a Polystyrene-Poly(methyl methacrylate) BlockCopolymer from the Azo-Containing Polystrene of A.

A mixture of 9g. of methyl methacrylate and l g. of the azo-containingpolystyrene from A above was heated at 75C under nitrogen in a sealedtube for seven hours. The resultant reaction mixture was taken up inbenzene and the block copolymer precipitated with petroleum ether. Afterdrying, it weighed 4.5 grams. Its infrared spectrum showed thecharacteristic absorption bands of polystyrene and poly(methylmethacrylate).

In a blank run, methyl methacrylate gave no polymer after 7 hours at75C.

Further evidence for the formation of a polystyrenepoly (methylmethacrylate) block copolymer was obtained from demixing tests as shownbelow:

Control Test No. 1 Test No. 2

The ability to stabilize is tested in the laboratory by empirical testswhere the stabilized solution is compared to a control solution. Thetime for the appearance of two distinct layers is measured. It is to beemphasized that the results cannot be used to compare effectiveness indifferent polymeric systems, since even polymer molecular weight cancause substantial changes in separation time between two systems madefrom the same monomers. However the laboratory tests are meaningful interms of screening potential stabilizers.

It is known that when two different polymers are brought in solutionreally a dispersion in a common solvent, over a period of time thesolution (dispersion) segregates into two layers (demixes), havingdifferent polymeric compositions. Apparently homogeneous melts of twodifferent polymers frequently on solidifytrogen in a sealed tube for 110 minutes. The cooled reaction mixture was dissolved in benzene andpoured into methanol to precipitate the peroxide-containing polystyrene,which after drying, weighed 3.2 g.

Its infrared spectrum showed the characteristic absorption bands forpolystyrene and the t-butylperoxy ester groups.

B. Preparation of a Polystyrene-Poly(methyl methacrylate) BlockCopolymer from the Peroxide- Containing Polystyrene of A.

A mixture of 2g. of methyl methacrylate and lg. of theperoxide-containing polystyrene from A above was heated at 85C undernitrogen in a sealed tube for 3 hours. After cooling, the resultantreaction mixture was dissolved in a benzene-acetone solvent mixture andthe poly(methyl methacrylate) homopolymer precipitated out by addinghexane, and filtered off. Removal of the solvents from the filtrateunder vacuum left 0.8g. of the block copolymer.

Its infrared spectrum showed the characteristic absorption bands ofpolystyrene and poly(methyl methacrylate).

Further evidence for the formation of a polystyrenepoly(methylmethacrylate) block copolymer was obtained from the demixing tests shownbelow:

Preparation of di[4-t-Butylazo-4-cyanovaleryl] peroxide.

cs o o cs 11 l t-CnH OOC (CH -C-Polystyrene A solution of 5 g of styreneand l g of the di-tbutylperoxy ester of cis-4,4'-azobis(4-cyanovalericacid) (from Example 4) was heated at 70C under ni- N CH Compound I whereR t-C H m 2, and n 1.

To a solution of 048g. (.012 m) of sodium hydroxide and 0.40g. (.006 m)of 50 percent hydrogen peroxide in 10 ml. water at 10C was added asolution of 2.7g. (.01 18 m) of 4-t-butylazo-4-cyanovaleryl chloride in10 ml. benzene over 5 minutes. After the addition was complete, thereaction was stirred an additional 6 hour at 10C and 15 minutes moreallowing the temperature to rise to 23C. Another 10 ml. benzene wasadded, the benzene layer separated, washed with 30 ml. 10 percent NaHCOsolution, 15 ml. water, dried over anhydrous sodium sulfate, filteredand the benzene stripped off. A white crystalline solid weighing 2.3g.(93 percent yield) resulted.

The product had a melting point of 87-88C with decomposition, 9192Cafter recrystallization from benzenepentane. The material assayed 100percent by l-ll CH analysis. The product was not shock sensitive and itsinfrared spectrum was in agreement with that of the dex fi t gm and nsired product.

The azo portions of the molecule have a 10 hour half- 5 life atapproximately 76C while the peroxide portion has a 10 hour half life atapproximately 63C.

m =1, and n 1.

To a solution of 4.15 g. (.0219 m) of 97.5 percent 2- EXAMPLE 9methyl-2-t-butylperoxy-4-hydroxypentane and 3 ml. of

Preparation of t-Butyl 4-t-butylaz0-4- l pyridine in 15 ml. either at 5Cwas added solution of cyanoperoxyvalerate 5.0g. (.0219 m) of4-t-butylazo-4-cyanovaleryl chloc o ride in ml. ether. A whiteprecipitate of pyridine hy- 3 & drochloride formed immediately. Theaddition of the (cH c-N-R-c-cfl -cfl Q0c(cfl3)3 acid chloride solutionwas carried out in minutes at I 15 5C. The reaction was stirred anadditional one hour at ON room temperature. The reaction mixture wasfiltered and the ether filtrate washed with 5 percent HCl, 10%

C d l h R t-C H Ompoun w ere 4 9 NaHCO' solution, water, dried overanhydrous sodium 033 0 sulfate, filtered and the ether stripped offleaving a light l brown liquid weighing 7.4g. (88 /2% yield).-C-Cl'l2cil2-, X lt g' n The product was chromatographed over aluminaand l eluted with pentane. Upon evaporation of the pentane, 6.3g. ofayellow liquid resulted. The infrared spectrum m 1, d n 1, of thepurified product was in agreement with that of To a solution of 2.7g.(.03 m) of 99 percent tthe desired product. The product was not shocksensibutylhydroperoxide in 15 ml. water at 5C was added tive.

3.74g. (.03 m) of 45 percent KOH. The solution was The azo portion ofthe molecule has a 10 hour halfcooled to 3C and a solution of 6.3g.(.0275 m) of 4-tlife at approximately 76C while the peroxide portionbutylazo-4-cyanovaleryl chloride in 10 ml. benzene was has a 10 hourhalf-life at approximately 126C.

added over fl hour holding the temperature between 3 and 5C. After theaddition was over, the reaction was EXAMPLE 1 1 stirred an additionalhour at room temperature. The Pr p n of y yl ne bi benzene layer wasseparated, washed twice with 10 per-(4-t-butylazo-4-cyanoperoxyvalerate) e l e e s (CH c-w-N-c: -cu cn -cool: 4:1 0:1 :ooc-ur cn 4|: -u-n-c CH 3 CN CH CH 0N cent Nal-lCO solution,once with water, dried over an- I Compound I where R t-C H hydroussodium sulfate, filtered and the benzene stripped off. A liquid weighing6.8g. (88 percent yield) CR was obtained. l

The product assayed 88 7% percent by an iodometric R 2 2-s analysis. Theinfrared spectrum was in agreement with l that of the desired productand there was no indication an of any residual t-butyl hydroperoxidepresent. The product was not shock sensitive. It slowly evolved nim nand trogen at 90C.

The azo portion of the molecule has a 10 hour half- CH CH 0 life atapproximately 76C, while the peroxide portion 3 I 3 has a 10 hourhalf-life above 102 C. -OQQC CH2CK2 C OOA EXAMPLE 10 l CH CH Preparationof 1,3-D1methyl-3-(t-butylperoxy)-butyl 3 34-t-butylazo-4-cyanovalerate. To a solution of 2.72 g. (0.0152 m) of2,5-dimethyls {3 (6K c-n-n-e-cn -crr -cocp-cn -c -o-o-cwu ON 3-. CH

Compound I where R t-C H 2,5-dihydroperoxyhexane and 5 ml. of pyridinein 30 ml ether at 10C was added a solution of 7.5g (0.0328 CH 0 m) of4-t-butylazo-4-cyanovaleryl chloride in 10 mls.

3 ether over 10 minutes. The reaction was stirred an ad- RI c..c cg co ccg ditional hour at room temperature and filtered to rel 1 move theprecipitated pyridine hydrochloride. The Q ether filtrate was washedsuccessively with cold 5 percent KOH, percent l-lCl, percent NaHCO;solution, saturated NaCl solution, dried over anhydrous sodium sulfate,filtered and the ether stripped off. A viscous liquid weighing 6.8 g.(79 percent yield) was obtained. The liquid solidified on standing inthe refriger- 5 ator. The solid was recrystallized from pentanebenzeneto a white crystalline solid with a melting point of 90-92C.

The infrared spectrum of the product was in agreement with that of thedesired product. An iodometric 1O hydrgperoxide d 1,6 g (,02 of pyridinei 25 ml analysis of the compound indicated there was 5.77 perth t 5C wasadded a solution of 3.0 g (,0] m) of cent active oxygen present(Theoretical active oxygen 2,2'-azobis-( Z-methylpropyl chloroformate)in 25 ml 5.65 percent). The product was not shock sensitive. ether. Theether solution of the chloroformatc was The azo portions of the mOleculehave a 10 hOur hal added dropwise with stirring over minutes, holding eat appr y While the PefOXide Portions 15 the temperature at 5C. Pyridinehydrochloride began have a 10 hour half-life at approximately 102C. toform immediately. The reaction was stirred an additional one-half hourat 5C and the pyridine hydrochlo- EXAMPLE 12 ride filtered off. Theether solution was washed succes- Preparation of sively with 2 percentPIC], 10 percent NaHCO solu 4,4-azo is[l1. y y p y) y l tion, saturatedsalt solution, dried over anhydrous socyanovalerate] dium sulfate,filtered and the ether stripped off. A liqr 0 r r r (CH COO-(l2-OH-ti7ttoC-CH -CH -(.2- =N-(l!-Gt -c!t -l:0 |n-l-CH f-O0-c(clt CH3 CH3 CHCN CH3 Q53 9 Compound I where R R'X and R uid weighing 1.8g. (44 &percent yield) resulted.

0 OH The infrared spectrum of the product indicated there ?"3 a 3 wasconsiderable OH present so the product was chrococn I matographed overalumina. The first cut was eluted CH2 x foocufig with 75 ml. pentane.Upon evaporation of the pentane m 353 p 03 there was 1.25g. ofacolorless liquid. An infrared spec trum of this material was inagreement with that of the m 1, and n 1. desired structure, with theexception of a small amount 0 8 Solution of gof Y of OH left. The samplewas assayed for percent tbutylperoxy-4-hydroxypentane and 5 ml. ofpyridine in butylhydroperoxide by a sulfite method and for total 25 m1-benZene was added a So uti of gactive oxygen by a FeCl method. Thematerial assayed of trans-4,-4'-azobis(4-cyanovaleryl chloride) in 25ml. 73 percent as the percarbonate and also contained 1.9 benzene at 20Cover 15 minutes holding the tempera- 40 percent t-butylhydroperoxide.ture at 20C. The reaction was stirred 1 hour after the The azo portionof the molecule has a 10 hour halfacid chloride addition was Over. Thepyri in hy r life at approximately 162C while the peroxide portionschloride was filtered off and the benzene filtrate h v a 10 hourhalf-life at approximately 99C. washed with 5% HCl, 10% NaHCO solution,saturated NaCl solution, dried over anhydrous sodium sulfate, EXAMPLEfiltered and the benzene stripped off. A viscous liquid Preparation of2,2'-azobis(2-cyano-5-t-butylperoxweighing 5.2 g. (85 percent yield) wasobtained. ycarbonyloxypentane) The infrared spectrum of the crudematerial indicated there was some unreacted alcohol present. A I 3 3 samle of 3.4 g of the crude material was dissolved in 5 ml benzene andchromatographed over alumina. The 3fi' )3ocooc(cu3)3 first cut waseluted with 75 ml pentane. Upon evapora- 0" ON 1 tion of the pentane 1.9g of a viscous liquid, which solidified in the refrigerator, wasobtained. The infrared C p d I where R R'X and R spectrum of the productwas in agreement with that of CH the desired product. The second cutcontained some of 3 v I the unreacted alcohol and was discarded.

The azo portion of the molecule has a 10 hour halfx o 9 life atapproximately 65C while the peroxide portions CN have a 10 hourhalf-life at approximately 126C.

m 1, and n 1. EXAMPLE 13 To a solution of 1.9g. (.0212 m) of 100 percenttbut lh droperoxide and 1.6g. (.0212 m) of pyridine in g gj f h l l b tl b l 25 ihl ether at 4C was added a solution of 4g. (.0106 1S[ qnet y(v u y veronica! ony oxy m) of 4,4'-azobis(4-cyanopentyl chloroformate)in 25 0 CH CH 0 ml. ether. The ether solution of the chloroformate wasii i J: J: added dropwise with stirring over 15 minutes holding EQB 2 Q(CH3)3 the temperature at 5C. After the addition was over the Compound 1where R R'X and R'= CH ll -C-CH X --O-COOC H -t,

m l, and n 1.

To a solution of 1.8 g (.02 m) of percent t-butyl reaction was stirredan additional hour at 10C, the pyridine hydrochloride filtered off, theether filtrate 3 ,860,674 23 24 washed with HCl, NaHCO solution,saturated (j b d I where R t-C H R NaCl solution, dried over anhydroussodium sulfate,

filtered and the ether stripped off. A liquid weighing 3 1 chug-t,

3.4g. (67 percent yield) was obtained. I The infrared spectrum was inagreement with that of 5 fi'm 3'* x the desired product. The productassayed 96 /2 percent by an iodometric titration and it was not shocksensitive. m=1,andn=1.

The azo portion of the molecule has a 10 hour halflife at approximately65C while the peroxide portions 10 T a solution of 1.8 g. (.02 m) of 100percent t-butyl have a 10 hour half-life at approximately Chydroperoxide and 1.6 g. (.02 m) of pyridine in 25 ml. ether at 5C wasadded dropwise with stirring a solution EXAMPLE of 5.2 g. 0.02 m) of4-t-butylazo-4-cyanopentyl chlo- Preparation ofDi(4-t-buty1azo-4-cyanopentyl) peroxroformate in ml. ether. After theaddition was comydicarbonate 15 plete, the reaction was stirred anadditional hour at {3 g 3 (W C-N-N- '3-(CH OCO0CO(CH (i-N-N-C(CH CN 0Compound I where R t-C H R 10C, the pyridine hydrochloride was filteredoff and 25 the ether layer was successively washed with 5% HCI, CH 0 010% NaHCO solution and saturated NaCl solution, dried over anhydroussodium sulfate, filtered and the fi x ether stripped off. A liquidweighing 5.8 g. (92 percent N yield) was obtained.

The infrared spectrum of the product was in agreem 2, and n 1. ment withthat of the desired product and the material To a solution of 102g.(0.0395 m) of 4-t-butylazo-4- was not shock sensitive. lt assayed 80.0percent by iocyanopentyl chloroformate in 30 ml. ether at 5C wasdometric titration. added dropwise with stirring a solution of 1.97g.(0.022 The azo portion of the molecule has a 10 hour halfm) of 38percent hydrogen peroxide, and 3.3g. (0.042 life at approximately 78Cwhile the peroxide portion m) of pyridine in 10 ml. ether. Thetemperature was has a 10 hour half-life at approximately 99C. held below10C during the addition period. The reaction was stirred an additionalone-half hour at 10C, the EXAMPLE l7 pyridine hydrochloride filtered offand the ether filtrate 40 A. Preparation of a Peroxide-ContainingPolystyrene washed with 2% HCl, 10% NaHCO solution, saturated from1,3-Dimethyl-3-(t-butylperoxy)butyl NaCl solution, dried over anhydroussodium sulfate, 4-t-Butylazo-4-cyanovalerate.

CH h) CH t-C B OOJI-CH CH-O-C-CH -CH -(i Polystyren'e filtered and theether stripped off. A liquid weighing A mixture of 15 g. of styrene and3 g. of 1,3- 7.55g. (80 percent yield) was obtained.dimethyl-3-(t-butylperoxy)butyl 4-t-butylazo-4- The infrared spectrum ofthe product was in agreecyanovalerate, from Example '10, in 36 g. ofxylene was ment with that of the desired product except for some heatedat 90C under nitrogen for 6 hours. The cooled OH present. The sampleassayed 60 percent by iodoreaction mixture was precipitated in odorlessmineral metric titration and was not shock sensitive. spirits. Theresultant polymer was dissolved in benzene The azo portions of themolecule have a 10 hour halfand reprecipitated from mineral spiritsthree times. The life at approximately 78C while the peroxide portionpurified peroxide-containing-polymer weighed 13.] g. has a 10 hourhalf-life at approximately 45C. B. Preparation of aPolystyrene-Poly(methyl methacrylate) Block Copolymer from the Peroxide-EXAMPLE 16 Containing Polystyrene of A.

Preparation of 0-4-t-Butylazo-4-cyanopentyl 0,0-t- A mixture of 15 g. ofmethyl methacrylate and 3 g. butylmonoperoxycarbonate of the aboveperoxide containing polystyrene in 36 g.

xylene was heated for 1 hour at 120C and 7 hours at 129C under nitrogenin a sealed tube. The cooled re- CH 0 i 3 g action mixture wasprecipitated in odorless mineral cu c c o 09 cu spirits. The resultantpolymer was dissolved in benzene 3)3 3)3 and reprecipitated from mineralspirits twice. The dried 0]! product weighed 12 g.

A 14 percent solution of the final product in chloromer was formed.

Additional species, coming within the scope of this invention, were alsoprepared, and are listed in Table III below. As with the previousexamples, proof of structure was accomplished by means of Infraredspectroscopy and active oxygen analysis where applicable methods wereavailable. The methods of preparation of some of these compounds followthe table.

table A86- Peroxide:

mm A8 TEN noun HALF-LIFE TEMPERATURE F IV I EXAMPLE mm AID mm Gu luusrrxvm T am E no PEROXIDE (CH3)3 m 0 A (cagcmw-hurgiflmg; en 18 Iliquid negative 90-100C Q576C anal-110C (C1193 k fls-blflt-butlgeroxflpontyl k-(t-hutyluol- -CIDOVI1QPBO O !00C(CH3)3 1 t 19 liquidnogutive 100% z 162C 3105 6 2,2'-uob1 l-[Z-(t-butylpe omen-bowl)-benzoyloxy Z-uethylpropunej 0 ED00165 f E0(c1i an ii uid negative 70%{365C ;:io5c

2 2'-nz Z-cyano-S- Z-(t-butylperoxycrirbonygge zoyloxyle tanej cs c11(CH C-N=N-!CH --0OC(CH3)3 21 N 8 ii uia negative 70% 7 5540% zi26c2-(t-butzylazc)-2-cyano- +-methyl- +-(t-buty1peroxy)pentnne m on Twosolid I 3 A 3 isomer! 0 o (ca co -ca -u= I negative mm c 5 c 2 DEC.

-gg o o ,2'-az0b1s[2-cyanov-metl1yl- 3 .3 c rial-t1" 90% no 0 126 c-(t-butylperoxy)-pentanej DEC.

3 *3 (c11 c-u=u- ':-cs -J:-ooc(cn 23 1 a liquid negative 35c 1.860%:126'

2-(t-hutyhzo)-2-chlorov-mthyl- +-(t-buty1peroxy)-pentlno m c11 '(ciic-u=u- Lcu -J:ooc(cu 2h 3 liquid negative zc 2126c 2- t-butyluo)-2-uthoxyv-lothyloJt-butylparoxH-pnntum flbl. III Cuminucd lzo-PnroxlduEXAMPLE STRUCTURE AND NAME FORM SHOCK SENSITIVITY 0A8 EVOLUTIONTEMPERATUBE E E A u psnoxms D1 +4.-(butylazo)- +-(p-L-buty1- thophenoxy) peroxide vlleryl solid negative i pe oxide liquid negativeliquid nagltive t-Butyl l2-(t-butylazo)-l2- cyano-peroxystearate liquidnegative 1,1 3,3-Tetramethylbutyl &-(t:-bu1.yl--azoi-N-azidoperoxyvalerate liquid negative (lul l,l 3 -Tetramethylbutylh-(t-butgylazoit-(p-t-butylthiophenoxy)peron'vnlerate liquid negativeon, 0 cu, cu,

1 ,1 3,j,-'lecramethylbutyl (L-bun lazo v-cyanoperoxyvalerate liquidnegative The following are descriptions of the procedures used toprepare many of the compounds in Table III.

EXAMPLE 21 Preparation ofZ-(t-Butylazo)-2-cyano-4-methyl-4-(tbutylperoxy)pentane Thet-butylhydrazone of 4-methyl-4-(t-butylperoxy)- 3-pentanone was preparedby the method described in Example 23 (below). To 21 g. of the abovetbutylhydrazone in a 60 ml. pressure bottle was added 10 ml. liquid HCNand the bottle stoppered and allowed to stand overnight. The nextmorening the solution was poured into 200 ml. water and extracted withpentane. The pentane layer was washed twice with 50 ml. of saturatedNaHCO solution and placed in a 500 m1. 4-neck round bottom flask with 50ml. of water. The temperature was lowered to 5C. with an ice bath andthen chlorine passed into the system holding the temperature below C.After 5.5 grams of chlorine had been added, the exotherm ceased. Thechlorine addition was stopped and the reaction allowed to stir anadditional one-half hour, the pentane layer separated, washedsuccessively with water, saturated NaHCO solution, water, dried overanhydrous sodium sulfate, filtered and the pentane evaporated on a flashevaporator. The residue weighed 14.1g and was a mixture of the desiredproduct, 4-methyl-4-(t-butylperoxy)-2- pentanone and some tarrymaterials. The desired product was isolated by column chromatographyover alumina with pentane as the eluent.

EXAMPLE 22 The compound of Example 22 was prepared in a similar mannerfrom the ketazine of 4-methyl-4-(tbutylperoxy)-2-pentanone and liquidHCN followed by oxidation with aqueous chlorine.

EXAMPLE 23 Preparation of2-(t-butylazo)-2-chloro-4-methyl-4-(tbutylperoxy)pentane4-Methy1-4-(t-butylperoxy)-2-pentanone was prepared by the addition oft-butylhydroperoxide to mesityl oxide. The t-butylhydrazone of4-methyl-4-(tbutylperoxy)-2-pentanone was prepared by refluxing asolution of equimolar amounts of t-butylhydrazine and4-methyl-4-(t-butylperoxy)-2-pentanone for 2 hours.

To a solution of 5.16 g. (.02 moles) of the tbutylhydrazone of4-methyl-4-(t-butylperoxy)-2- pentanone in 25 ml. of pentane in a 100ml. 4-neck flask, precooled to 0C, was added 1.42 g. (0.02 moles) ofchlorine over a minute period. The reaction was stirred for anadditional hour at 0C and then filtered to remove the white solid whichformed during the chlorination. The pentane filtrate was evaporated on aflash evaporator to give 3.8 grams (65 percent yield) of the desiredproduct.

EXAMPLE 27 The 2-bromo derivative of Example 27 was prepared in asimilar manner to the 2-chloro derivative of Example 23 by the additionof bromine instead of chlorine.

EXAMPLE 28 Preparation of 2,2'-Azobis(2,3-dimethyl-3-hydroperoxybutyronitrile) on, ex, on, ca,

H00-d-d-lt=1i-( ;-d-00l1 AH d1 do 1H;

A. Preparation of 2,2'-Azobis(2,3-dimethyl-3- hydroxybutyronitrile) Theketazine of methyl hydroxy butanone was prepared in 98 percent yield byrefluxing 0.] moles of 85 hydrazine hydrate and 0.2 moles of methylhydroxy butanone with 25 ml. of benzene and removing the water formed bymeans of a Dean Stark trap.

To a pressure bottle containing 18.7g of the above ketazine, was added25 ml. of liquid HCN, the bottle stoppered and allowed to standovernight at room temperature. Upon standing overnight a solidcrystallized out. The liquid portion was decanted into a stirredsolution of NaOH to convert the HCN to NaCN. The solid was broken up,slurried in 50 ml. water, filtered and dried. It weighed 14.8g. and hada melting point of 145147C.

The hydrazo was oxidized with chlorine in a methylene chloridewatersystem, washed with saturated NaH- CO solution, and the methylenechloride solution of the azo dried, filtered and the methylene chlorideevaporated on a rotating evaporator. The product weighed 14.4g and had amelting point of 123-125C.

B. Preparation of 2,2-Azobis(2,3-dimethyl-3- hydroperoxybutyronitrile)To 14.0g of H SO which was stirred and cooled to 0C was added dropwise15.8 grams of 50% H 0 followed by 40 ml. CH Cl To the stirred reactionmixture was added portionwise 15.1 grams (0.06 moles) of 2,2-azobis(2,3-dimethyl-3-hydroxybutyronitrile) over one-half hour at 1C. Thetemperature was allowed to rise from 1 to 25 over a 2 hour period andthen stirred at 25 for 3 hours longer. The methylene chloride layer wasseparated, washed with 40 percent (NH.,) SO solution, water, dried overanhydrous magnesium sulfate filtered and the methylene chlorideevaporated on a rotating evaporator to leave 13.0 grams of a mushysolid. The solids were slurried up in pentane and refiltered to give 10grams ofa white solid melting at 83-85C. The solid assayed 74 percent asthe desired product by iodometric titration. The pentane filtrate wasevaporated to dryness to give 2.5 grams of a liquid which assayed 70.7percent as the desired product. Infrared analysis indicated that the twomaterials were most likely isomers.

EXAMPLE 30 Preparation of 2-(t-buty1azo)-2-(p-tbutylthiophenoxy)-4-methyl-4-(t-butylperoxy)pentane l C (en, To astirred solution of 1.38g (.021 moles) of 85 per cent potassiumhydroxide in 25 ml. of methanol in a 125 ml. erlenmeyer flask was addeddropwise 3.66 grams (.022 moles) of p-t-butylthiophenol. The reactionwas stirred an additional 30 minutes and then 6.0 grams (.0205 moles) of2-(t-butylazo)-2-chloro-4- methyl-4-(t-butylperoxy)pentane from Example23 was added dropwise over 30 minutes, holding the reaction temperatureat C with a cold water bath. The reaction was stirred an additional hourat room temperature and poured into 100 ml. of water. The product wasextracted with 50 ml. of pentane, the pentane solution washed withwater, dried over anhydrous sodium sulfate, filtered and the pentaneevaporated on a flash evaporator. The residue weighed 8.65g (72 percentyield) and its infrared spectrum was in agreement with that of thedesired product.

Examples 24, 25, 26, 29, 31, 32, 33 and 35 The 2-methyl, 2-azido,2-acetoxy, 2-phenoxy, 2- thiocyanato, 2-dodecanethiol, 2-thioacetoxy and2-tbutylperoxy derivatives of Examples 24, 25, 26, 29, 31, 32, 33 and 35were prepared by similar reactions, i.e. reacting the2-(t-butylazo)-2-chloro-4-methyl-4 (t-butylperoxy)pentane (from Example23) with approximately equivalent amounts of the corresponding sodium orpotassium salt in alcohol i.e. either sodium or potassium methoxide,azide, acetate, phenate, thiocyanate, thiododecanoxide, thioacetate, andt-butyl hydroperoxide.

EXAMPLE 34 Preparation of2-(t-butylazo)-2-phenyl-4-methyl-4-(tbutylperoxy)pentane To a solutionof 8.0 grams (0.0274 moles) of2-(tbutylazo)-2-chloro-4-methyl-4-(t-butylperoxy)pentane (from Example23) in 150 ml. of pentane in a clean, dry, nitrogen purged 500 m1.reaction flask equipped with a mechanical stirrer, thermometer, andcondenser with drying tube, was slowly added 9.3 ml. (.028 moles) of a 3molar ether solution of phenyl magnesium bromide. The reactiontemperature was kept at to C, with a cold water bath. After the additionwas complete, the reaction mixture was stirred an additional minutes at15C. Ice chips were then added to the reaction to slowly destroy theexcess phenyl magnesium bromide. The reaction mixture was poured into200 ml. of water, the pentane layer separated and washed successivelywith 10% HCl, water, saturated NaHCO solution and water. The pentanesolution was dried over anhydrous sodium sulfate, filtered and thepentane evaporated on a flash evaporator. The residue weighed 5.7 grams(62% yield) and the infrared spectrum was in agreement with thestructure of the desired compound.

EXAMPLES 36 to 45 The compounds of examples 36 to 45 were prepared fromthe corresponding azo acid chlorides using the procedure described inExample 8 for the axo-diacyl peroxides and the procedure described inExample 9 for the azo-peroxyesters.

Many compounds of the present invention are taught in the aboveexamples. some additional compounds of the subject invention which maylikewise be prepared are illustrated below and many more will be obviousto those skilled in the art:

CH3 ca,

1 l l I cm ca, v

9 ca, oliotcs, 1 cs in m an, 0 on, ca,

t-bu-lhlv-S (C11 miltnl-ti-ch Ji-CH,

(in, 411', is,

1. FORMING A POLYMER HAVING PEROXY GROUPS PRESENT BY REACTING VINYL-TYPEMONOMER AND AN AZO-PEROXY COMPOUND UNDER VINYL POLYMERIZATIONCONDITIONS, CONTROLLING THE CONDITIONS IN ORDER TO CAUSE THE AZO-CARBONLINKAGES TO RUPTURE PRIOR TO RUPTURE OF THE PEROXY-OXYGEN LINKAGES, SAIDRUPTURE OF THE AZO-CARBON LINKAGES HAVING THE EFFECT OF INITIATING SAIDPOLYMERIZATION; AND
 1. FORMING A POLYMER HAVING AZO GROUPS PRESENT BYREACTING VINYL-TYPE MONOMER AND AN AZO-PEROXY COMPOUND UNDER VINYLPOLYMERIZATION CONDITIONS, CONTROLLING CONDITIONS IN ORDER TO CAUSE THEPEROXYOXYGEN LINKAGES TO RUPTURE PRIOR TO RUPTURE OF THE AZO-CARBONLINKAGES, SAID RUPTURE OF THE PEROXY-OXYGEN LINKAGES HAVING THE EFFECTOF INITIATING SAID POLYMERIZATION; AND
 1. REACTING STYRENE WITH ANINITIATING AMOUNT OF AN AZOPEROXIDE,
 1. REACTING A XYLENE SOLUTION OFSTYRENE WITH AN INITIATING AMOUNT OF AN AZO-PEROXIDE,
 2. REACTING AXYLENE SOLUTION OF METHYL METHACRYLATE AND THE PEROXIDE CONTAININGPOLYSTYRENE OF STEP (1) IN A NITROGEN ATMOSPHERE AT 120*-129*C FOR ABOUT8 HOURS.
 2. A METHOD OF PREPARING A POLYSTYRENE-POLY(METHYLMETHACRYLATE) BLOCK COPOLYMER WHICH METHOD COMPRISES:
 2. REACTING METHYLMETHACRYLATE WITH THE AZO CONTAINING POLYSTYRENE OF STEP (1) IN ANITROGEN ATMOSPHERE AT 75*C FOR ABOUT 7 HOURS.
 2. REACTING VINYL-TYPEMONOMER WITH THE POLYMER OF STEP (1) UNDER CONDITIONS TO RUPTURE THEAZO-CARBON LINKAGES OF SAID STEP (1) POLYMER TO PRODUCE A BLOCK POLYMERPRODUCT, SAID AZO-PEROXY COMPOUND HAVING THE FORMULA: ((R-N=N-R'')M-X)N2. REACTING VINYL-TYPE MONOMER WITH THE POLYMER OF STEP (1) UNDERCONDITIONS TO RUPTURE THE PEROXY-OXYGEN LINKAGES OF SAID STEP (1)POLYMER TO PRODUCE A BLOCK POLYMER PRODUCT, SAID AZO-PEROXY COMPOUNDHAVING THE FORMULA: ((R-N=N-R'')M-X)N
 3. A METHOD OF PREPARING A BLOCKPOLYMER WHICH METHOD COMPRISES:
 4. A METHOD OF PREPARING APOLYSTYRENE-POLY(METHYL METHACRYLATE) BLOCK COPOLYMER WHICH COMPRISES: